Force of Nature
by railou
Summary: Following the events he went through in Kalos, Ash is really hoping he could spend some much needed time just resting and relaxing and showing Greninja around the beautiful beaches of Alola. But unfortunately, the world needs saving, again, and Ash is the only one who can help. Again. (Set immediately after Together We Are Stronger, featuring Aura-user Ash and Worried Papa-Kukui)
1. Nature's Madness

**Hi guys!**

**I sat on this idea for _months_ until I figured out how to actually write it. I also wrote almost 3 000 words for this fic before realizing it wasn't what I wanted and started again from the scratch.**

**But here we are, finally! I really hope you enjoy it.**

**.**

**SET AFTER MY OTHER FIC, **TOGETHER WE ARE STRONGER

* * *

_Move: Nature's Madness_

_The user hits the target with the force of nature._

_._

_._

_Ash_

_._

For Ash, coming back to Alola with Greninja and with his Aura and with the memory of dead Lysandre is… different.

The first morning back in Alola, Pikachu wakes him up by pawing on his face and sparking him with static electricity that makes his skin tingle and his hair stand up on end. Ash blinks blearily, his head feeling stuffy and his body heavy from deep sleep. He sits up slowly, but regardless of his efforts to move carefully, the change in position makes his head spin – he knows he's still recovering and will be for a while longer, but it annoys him, nonetheless. It's been three days since he got out of the hospital and he feels more than ready to get back to normal life already.

Ash glances out of the window and sees that the sun has risen a while ago, the sky vibrant blue with the tropical brightness of Alola. Ash fights against an urge to pull the blanket over his head and go back to sleep, and instead looks down. On his lap, Pikachu is looking at him with scarily perceptive eyes and Ash hides his face for second by running a hand through his tangled mop of hair.

"Mornin', Pikachu", he mumbles through a yawn. Pikachu's tail whips around eagerly, and Ash can't help but smile at its excitement. He hears the Professor shuffling around in the kitchen downstairs, and he glances around the loft – his second home – and it hits him then that he's back. Really back. Safe.

"It's so great to be here again, isn't it?"

Pikachu coos happily. Ash gets up, slowly, carefully, and pulls on his sneakers and changes his shirt. He grabs his hat from the nightstand, rolls his shoulders and grimaces how stiff and sore his right one still feels. He's had a lot worse, for sure, but this will definitely make performing Z-moves uncomfortable for a while.

Well, he shouldn't complain, really. Lysandre, for one, is dead, after all. You don't get much more hurt that that.

Ash climbs the ladder down carefully and by the time he turns around at the bottom Kukui is already standing there, watching him with warm eyes.

"Good morning, Ash", he says, and he smells like breakfast food and coffee and affection. "I hope you slept well."

Ash chuckles, suddenly embarrassed by the late hour. "I did, thanks Professor. Man, sorry, I slept so late! It's probably way past midday already."

He rubs the back of his neck and Kukui purses his lips, a strange look passing on his face before it's replaced with a bright smile. "Don't worry about it!" he grins. "Come on, the food is just about ready. You must be famished!"

"Thank you, I sure am!"

Kukui hands him a plate and on his way to the table Ash walks by a window and leans forward to look through it. It's open, and when a breeze of salt-laced wind blows in and ruffles his hair and the sunlight hits his face and he hears the ocean waves hitting the rocks on the far side of the beach, it's like a shock that runs through his body and his Aura is suddenly _awake. _

He's vaguely aware of dropping the plate, the porcelain smashing against the floorboards and the carefully prepared breakfast flying everywhere. Kukui and Pikachu's voices are drowned out by something much louder, something much more intense, and he stands absolutely still and just _listens_.

The power – the _energy_ of Alola crashes through him like a wave from a tsunami, encapsulating him, and even though it overwhelms his senses, it also feels familiar, somehow. He realizes then that he has always been able to feel it, to some extent. Now, with his newly released Aura it's thousand times stronger, like what he heard before had been the sound of a single instrument playing and now, finally, he is hearing the whole orchestra.

He's had a few days to practice living with his Aura, but back in Kalos he had still been so tired, so exhausted, and his Aura had remained mostly dormant, just brimming under his skin but not reaching out unprompted. He had though he had it more or less under control. After successfully using it against Lysandre, and living through the following days… Nothing really had changed, right?

But it's dawning on him now that he does, indeed, _not_ have it under control.

At all.

An actual shock of electricity runs through him then, and he finds himself on the floor. The world snaps into sharp focus and Ash blinks away his confusion. Alola is still singing to him, but it's faded now, farther away. Kukui looms over him and Ash looks up, eyes blown wide and hair sizzling.

"Ash?" says Kukui, and it sounds like he has been repeating the word for a while now.

"Uh", Ash answers, rubbing a shaky hand down his face.

"You with me?" the Professor asks, cautiously.

Pikachu is nudging his leg and Ash sets his hand on its fur without thinking, the move as natural as if the pokemon is an extension on his own body. It's a silent thank you, and he knows that Pikachu understands. It never enjoys shocking Ash, but it won't hesitate to do it if it deems it necessary.

"Y-yeah", Ash chokes out, scrambling to stand up.

"Are you okay? What happened?"

Kukui hovers next to him, slightly closer than is normal, like he's preparing to stop his fall at any moment.

Ash hesitates. "I… My…" He shrugs helplessly. "My Aura, uh, it did something, I guess?"

The Professor quirks an eyebrow but his shoulders relax, and he steps back, smiling.

"Your Aura, huh?"

It's not really a question, but Ash knows how curious Kukui is, and how interested he is in the topic. And, now that he's got his Aura somewhat back under control, he can also sense the excited energy emanating from the Professor, the _need_ to know more, to _understand_.

Kukui is also the person who currently knows most about his Aura, so he may as well try to explain it. He might learn something, too.

"Yeah", Ash says slowly, leaning against the kitchen counter. He glances at the floor and at the mess he made on it, before looking back up at Kukui. "I dunno why it didn't happen sooner, or in Kalos or anything, but there is this… this melody? In Alola? I dunno how to explain it any better, Professor, but it suddenly just hit me really hard and for a moment it was the only thing I could focus on."

"A melody? Could it…" murmurs the Professor, eyes far away. After a moment, his mouth stretches into a grin and he looks at Ash with bright eyes. "Yes, it must be! Ash, what you are hearing must be the life force of Alola!"

"Life force?" Ash intones.

At Ash's blank look, Kukui smiles even wider and continues: "Nature's power, Ash! Alola is famous for the harmony and balance that exists between people, pokemon and our beautiful nature! The sea, the forests, the vegetation… it all holds enormous power in and of itself! And the way we all live together and cherish that balance here in Alola, it lets us all share and gain that energy from each other. And Aura is… it's the essence of every living creature. It's the energy that exists in everything, though only few have the capabilities of controlling it. It's truly amazing, Ash, what you can do…"

He has moved closer again, and he stares down at Ash with a frantic glint in his eyes and Ash takes an instinctive step away, his spine digging into the countertop. He blinks and -

_Lysandre steps forward, his eyes wide with wonder. The room is still and unmoving around him, almost suffocatingly so. "Is that… your Aura?" Lysandre asks, sounding genuinely astounded. He advances on Ash slowly, cautiously. His arm reaches towards him, greedily, wanting to control, wanting to dominate_ –

His hand slides on the countertop and he stumbles backwards, the words slipping through his lips before he can stop himself: "Stay away!"

"Pikapi!"

Ash slaps a hand over his mouth and stands up with his back ramrod straight, dread pooling in his stomach. "I'm sorry!"

He lets his hand drop and looks at Kukui, his pulse thundering in his ears. "I'm sorry", he repeats. "I didn't mean to- You don't… I-"

"It's okay", Kukui says, and his voice is very gentle. "I got too excited and I startled you. I'm sorry."

He steps to the side, picking up a towel on his way. Ash knows he tries to look casual, but he can see his hands trembling, the muscles in his jaw working. And even more clearly, Ash can sense the alarm and the concern that surrounds the Professor like grimy, awful blanket.

It's almost exactly the same as what happened in the park in Kalos, and Ash _hates_ it. He feels like he doesn't know himself anymore. He wasn't like this before; he hasn't ever been this…

(afraid)

"I'm not like this, usually", he says out loud, and Kukui stills. His fingers tighten around the towel and he looks at Ash with an unreadable look.

"I'm not scared of you or anything, Professor", Ash continues resolutely, since he might as well finish what he started. "I dunno what's gotten into me lately, but it's got nothing to do with you. So don't worry! I'm sure it's gonna pass soon and then I won't do stupid stuff like that again."

He nods firmly. That's what's going to happen. He's decided.

Kukui worries his lip for a moment.

"It's not 'stupid stuff'", he eventually says. His voice is quiet and serious. "Ash, it's perfectly normal to feel anxious or on edge after a huge event like what you just went through. It's true that sometimes these feelings and reactions pass with just time, but sometimes it helps if you can talk to someone about it. Sometimes those negative emotions and fears coil up so tightly inside of you that they won't just go away on their own – they might even feed on each other and get worse, if left alone."

He breathes out, slow and steady. "Sometimes it takes years to recover, even _with_ professional help."

Ash glances at Pikachu, and the pokemon looks back, ears lowered and eyes wide.

"…Years?"

"Did your doctor speak to you about therapy, Ash?" Kukui asks softly.

Ash nods. "Yeah, like how I'm gonna visit a nurse at some point and they are gonna move my shoulder in every direction and see it if works all right."

Kukui's lips twitch. "That's _physical_ therapy you're thinking about. I mean psychotherapy. That is aimed to improve your mental health and help you work through your problems or any troubling thoughts that might impair your daily life. There are professionals out there who have been specifically trained to help people recovering from traumatic events, people exactly like you."

Ash bounces on his spot, fidgeting with his Z-ring. He looks to the side, through the open window. "Man, I dunno about all that", he sighs, and his voice sounds faint in his own ears. "I could just talk to you, right? Or to my friends, if I gotta. But really, I'm just fine."

Kukui tips his chin, his shoulders dropping. "All right, I believe you." He smiles. "But think about it, okay? If you ever feel like it's too much to handle on your own. And of course, you can talk to me anytime you want, about _anything_. I mean it."

"Yeah, okay", Ash agrees, and he smiles too. It feels genuine, and a pocket of warmth spreads though his body. "Thanks, Professor. It's good to know I'm not going mad or anything. Usually it just isn't like this for me after… well, after anything that happens."

He thinks how he has died before, (almost), and he has always been perfectly fine afterwards. This time shouldn't be any different.

Kukui looks like he doesn't really grasp what he means, but he smiles anyway. "You are definitely not going mad. But I know what you must be, and that's hungry! Come on, let me clean this up and you can eat from this other plate. It's probably gotten cold already, but it should still be good."

Ash takes the offered dish uncertainly. "If you're sure…"

Kukui kneels down and begins wiping away the food and shattered pieces of porcelain. "Of course I'm sure", he says, and it leaves no room for argument. Ash sets the plate down and picks up a bag of poke chow. He pours it in three cups and takes out his poke balls.

"Come out, everyone! Breakfast time!"

Litten, Rowlet and Lycanroc pour out of the poke balls with excited shrieks, first tagging him with licks and affectionate nudges and then crowding around the poke chow. Pikachu chirps happily and rushes to join them, while Greninja stands back and looks around with curiosity in its sharp eyes. Ash sets another cup of poke chow on the table and pats the sofa next to him, gaining Greninja's attention.

"Welcome to Professor Kukui's home, Greninja! I will show you around soon", he grins, "but let's eat first!"

.

Kukui disappears at some point while they eat and returns with newly re-activated Rotom Dex. It dashes across the room and almost hits Ash square in the head in its excitement.

"Ash!" it squeals. "You're back! Professor Kukui told me I was offline for a couple of days and you came back already! Bzz! I was so worried! Are you okay? What happened?"

Ash hurries to empty his mouth and grins at Rotom. "I'm just fine! Great to see you again, Rotom Dex!"

"Don't get too excited, Rotom Dex", warns Kukui from the kitchen. "We only just came back yesterday, and Ash needs a lot of time and space to rest. I think it'd be best if you don't ask too many questions in the meantime."

"Bzz, I understand completely! I won't ask Ash about anything personal, and instead I will let him recover in peace!"

"Thanks, Rotom", say Ash with a chuckle. "I will tell you what happened sooner or later, don't you worry. I guess I just need some time to think it through by myself, first."

"I totally understand! Hey, who is that pokemon?"

Rotom surges up and snaps a picture of a confused Greninja. "Updating… Oh, A greninja! I have never seen one before! You must be the pokemon Ash was talking about!"

Greninja waves its hand.

"Ninja."

"Yeah, Greninja is my great friend I got in Kalos! I think you'll need to do a lot of updating, Rotom Dex, once you see what me and Greninja can do together." He grins, his fingers curling with excitement. He turns to his team of pokemon. "Hey, have you guys finished eating yet? I wanna show Greninja around already!"

Ash jumps up and his blood pressure drops. His vision blurs and sparks with dark spots and he sways, presses a hand against his forehead and promptly sits back down with a huff. He can _feel _Kukui's long-suffering look on the side of his head and he looks up with an embarrassed grin.

Kukui is smiling lopsidedly at him.

"Try that again, but with more care this time."

Laughing, Ash stands up, and his pokemon gather around him, tails wagging and eyes sparkling. "Alright!" he starts, pumping a fist. "Let's go out and show Greninja around!"

They rush towards the front door. "Be back before dark!" Kukui calls after him.

Ash waves, grins over his shoulder and shouts: "I sure will!", and then he's off, fickle, like the wind from the far ocean that's promising a storm incoming.

_._

_._

_The Professor_

_._

He's not back before dark.

Kukui spends the day working, updating his lesson plan – when half of your class misses a week of school, there's no way to stay on the normal schedule – cleans the house and makes dinner for two. The food is left sitting cold an untouched on the stove, lone and waiting.

Sun sets and the sky gets dark and Ash is not back yet. Rain is starting to trickle down and the winds are increasing and sadly, the weather forecast was not wrong this time, either. Despite the bad weather, Kukui is sitting on the porch, debating whether to alert the police force for an island-wide search or if he should wait just a few more hours, when he gets a phone call from Lana, of all people.

"Hi, Professor", she greets, appearing on the screen with a reddish face and windblown hair. "Just thought you might wanna know that Ash is staying over tonight."

The relief is a physical thing, though Kukui does his best to keep his expression neutral. "He's at your house?" Lana nods, so Kukui continues: "Could I talk to him? He didn't say he was going to meet anyone today, so I was starting to get worried."

(Possibly the understatement of the year, but _she_ doesn't need to know that.)

But then, Lana hesitates, and it makes warning bells ring in Kukui's head at full force.

"Uh, he's already asleep", admits Lana, looking to the side and worrying her lip. "He was kinda… well, I'd rather not wake him up, if that's okay."

_Shit._

"Okay, what happened?" demands Kukui, and he has to work hard to keep his voice steady.

Lana throws her hands up, shrugging. "Nothing – well, I dunno, really. About half an hour ago, when me and Mallow were on my dad's rowing boat, fishing near the coastline-"

"You were out fishing?" barks Kukui. "This late?"

"That's not the point here, Prof..."

"Right, okay, so what then?"

"So, suddenly Ash appeared out of the forest with Pikachu and Rotom Dex and Greninja. He sat down on the rocks and when we paddled closer, we saw that they were all sweaty and dirty, and Ash told us he had a huge battle with Tapu Koko and he thinks that something big is about to happen soon…" Lana pauses, waves a hand uncertainly. "It was weird, and we were obviously a bit worried. He was all pale and kinda didn't make much sense, so I invited him over – and Mallow was gonna stay the night anyway. We made him eat a sandwich and he conked out almost instantly after that."

"Okay, good, okay", breathes Kukui, since he doesn't know what else to think or say.

"Yeah", says Lana. "He really needs to take a shower, but I think he's pretty much fine otherwise."

"How about Pikachu and Greninja?" Kukui asks. "Were they hurt? Do they need to be taken to a pokemon center?"

Lana shakes her head. "They seemed fine. Dirty and exhausted like Ash but I don't think they were injured. And I bet Ash would've taken them to a center himself if they were."

"You're right, he would", Kukui agrees. He takes a deep breath, trying to sort through the jumbling mess of his thoughts.

He comes to a decision a moment later. "Alright, so, if you're sure everything is fine for now, maybe I should come by in the morning and pick him up. I'll drive by and ring the doorbell at about eight o'clock, okay?"

Lana nods. "Sounds good." She yawns, big and unapologetic. "We'll be fine. Don't worry."

"I can't help it, you know", Kukui says with an edge of a smile. "Have a good night and see you in the morning."

"Good night, Professor."

Kukui stares at the darkened screen until his stomach grumbles angrily, making itself known after a full day of negligence. He tugs at his unwashed hair and shuffles to the kitchen to get a serving of cold pasta for one.

It's going to be a long night.

.

He's dozing off on the sofa when the shrill sound of the home telephone wakes him up.

It's still dark outside, the closed windows rattling with gusts of wind and heavy downpour, and he checks the time as he shuffles to the phone – it's half past five in the morning.

"Alola… Mallow? What's wrong?"

She's in her pajamas and her hair is plastered against her face and neck, soaking wet. Her eyes are wide and red-rimmed and she's speaking before the image even properly loads.

"He's gone, Professor!" she yelps. "Rotom just woke us up and, and – Ash is gone! We don't, we didn't see-"

Kukui's pulse picks up and he leans closer to the screen. "Hold on, just take a deep breath and start from the beginning. Mallow. It's all right."

"Yeah, okay, um…" She brushes the wet strands of hair away from her face, closing her eyes for a couple of seconds.

"So, Ro-rotom said it woke up from sleep mode just as Ash and Pikachu were leaving the guest room… Um, it followed them outside and saw Ash talking to Tapu Koko and Tapu Fini..."

_…Tapu_ Fini_? The guardian deity of Poni Island?_

Kukui has no idea how his face looks right then, but it must be a sight to see judging by Mallows expression. She waves her hand, fidgety and anxious.

"Rotom didn't hear the whole conversation, but it heard Ash saying something like '_you want to take me to Poni Island_?' And then, uh…" She shrugs, eyes wide. "Apparently, Tapu Koko grabbed Ash and Tapu Fini grabbed Pikachu and then they just… flew off!"

Kukui feels like he's still dreaming. He shakes his head. "Tapu Koko… took Ash? To- to Poni Island?"

Mallow nods glumly. "Yeah, that's what Rotom Dex says. Of course, Lana and I ran outside immediately, trying to catch up to them. Lana is still out there, looking… But it's pitch-black and raining like crazy and the wind is so strong… I'm sorry, Professor! We let him disappear like that…"

Kukui's stomach drops. "No no, don't think of it like that! This is in no way your or Lana's or anyone's fault. If the Tapu are involved…"

_…Who knows _what_ is going on_, he finishes silently, his mind going mile a minute trying to work out a reasonable explanation, _anything,_ that would explain this.

Her shaking voice brings him back to the present. "Wha-what do we do, Professor?"

He looks her sternly into the eyes. "_You_ don't do anything. Get Lana back inside and _stay_ inside. I will take care of this from now on."

"But-"

"Don't." Kukui sighs. "Look, I promise I'll tell you what's going on as soon as I find something out. But until then, I just need you two to stay safe. Can you promise me that?"

Mallow nods shakily. "Y-yeah, okay."

"Good." He attempts a smile, and Mallow does, too. Kukui says: "Try to get some rest. We will find him, don't worry. I'm sure Ash is just fine."

"Yeah. Thank you, Professor."

They end the call and Kukui slumps down on his chair, massaging his temples.

He just needs a moment to _think._ There's a storm raging outside, so no ferries are moving… There's no active Island Kahuna on Poni Island… Who should he contact first, then?

Alerting the actual police is sounding a better plan of action by the minute.

The frustration – the feeling of _helplessness_, it makes him irritable, and when his mobile phone rings then, he picks it up without looking.

"What is it?" he snaps.

"Hm, charming", drawls Burnet's voice. "Did I interrupt your beauty sleep, Professor?"

Kukui curses silently. "Ah, no. I'm sorry. What's up, Burnet?"

"Ooh, very exciting things!" she gushes. Kukui can hear a flurry of background noises on her end, machines beeping and people shouting. "We just got some very promising readings on our ultra-wormhole research! A large spike of energy alerted our systems, and we were able to pinpoint it over the far southwest of Alola. Kukui, it looks like it's really happening this time!"

_...What?_

Kukui blinks. Then he blinks again, since Burnet's words are still not making any sense.

"I-I think I misheard you", he stutters. "What did you just say?"

Burnet laughs – a sound that usually is music to Kukui's ears but this time, it's making his foot tap anxiously against the floorboards.

"Sweetie, you must be really tired", she chuckles good-naturedly. "I'm telling you that an ultra-wormhole is about to appear over Poni Island!"

* * *

**.**

**Note: You might remember from TWAS that this story is set at the end of season one of Sun and moon, so no ultra-stuff has yet happened in canon!**


	2. Guardian of Alola

**I had a job interview today, so here's a new chapter for some stress relief. Pls be kind to me. **

**.**

**This is it for the main story-line of this verse, I think. I might add some one shots/character studies later if I feel inspired, but otherwise, I hope you enjoyed this story and had as much fun with it than I did! Thank you for all the love and support you gave me on the way. Much love!**

* * *

_Move: Guardian of Alola_

_The user obtains Alola's energy and attacks the target with full force._

_._

_._

_The Professor_

_._

Through the buzzing in his ears, Kukui can hear Burnet speaking, telling him about the data, the massive spike of ultra-wormhole aura that they picked up, how they are about to board the plane and head over to Poni Island right about now-

Kukui blurts out: "Take me with you."

Burnet pauses.

"Excuse me?"

"Come pick me up and-" Kukui inhales shakily, forces himself to calm down. "I mean, _please_, Burnet, could you come pick me up and take me with you? I- I need to get to Poni Island, I…"

His voice breaks and he can hear Burnet taking a sharp breath. She's walking away from the commotion, speaking into the phone in a hushed tone.

"Kukui? What's wrong?"

Of course she can tell. She always could. He loves her so much right then that it hurts.

"It's- it's Ash", he chokes out. "He, um…"

"Oh shit, you just got back yesterday, didn't you", Burnet says, worry lining her words. "Poor boy, is he doing okay?"

Bless her, thinks Kukui, she hasn't even met Ash yet, not properly, but she already loves him just based on what, and how much, Kukui has been telling her about him.

So, when he doesn't reply immediately, she makes some conclusions. She has always been smart.

"Wait, why do you need to get to Poni Island again, at this hour of night? You don't mean that… Ash is…"

"Yeah."

Burnet is silent on the other end, waiting. Kukui swallows heavily. "I didn't see it myself, but Ash's Rotom Dex says that Tapu Koko and Tapu Fini appeared just moments ago and- and took Ash with them. To Poni Island."

"Tapu Koko- Tapu _Fini_ did?" Burnet repeats blankly. Kukui can almost hear the gears turning in her sharp mind. "Shit, Kukui", she continues then, "why _on earth_ would the Tapu take _a child_ to the site of an _ultra-wormhole_, in the middle of the night, during a huge storm?"

Her tone rises with every word and Kukui nods along emphatically.

"I really wish I knew", he says, desperation leaking into his voice. "Burnet, honey, can you…"

She replies before he can even finish the question. "Yes, I'm on my way to Lusamine right now. Just sit tight, Kukui, we will be there in about ten minutes."

Kukui closes his eyes. "Thank you", he breathes. "_Thank you_."

"It's going to be okay, sweetie", Burnet says quietly. "I'll see you soon. I love you."

"I love you too."

And he's left alone again, staring at his trembling hands as the minutes tick by, agonizingly slow.

.

.

_Ash_

_._

He's freezing, soaking wet to the bone, and all he can see is rain and clouds and the raging ocean below him.

As Tapu Koko carries him to gods know where, he wonders if it was all that smart to agree to this so easily.

Probably not.

Pikachu is miserable in Tapu Fini's arms, and Ash attempts to give it a reassuring smile, with not much luck. Then, he tries to solidify his Aura into a shield against the wind and rain, but his control is still limited and it's fickle at best, doing very little to cover them. In the end, he gives up trying and settles on hanging limply in Tapu Koko's claws, greatly regretting his life choices.

Luckily, it's not too long a journey from Melemele to the next island, not with the speed and power the guardian deities possess. When the Tapu then begin their descent, his feet brush the ground before he even properly has time to prepare for it. Tapu Koko drops him off on a rocky hill, leaving him standing there, his head spinning with the sudden change of pace. Pikachu jumps on his shoulder and Ash shudders as its cold and wet fur brushes against his neck – not that his neck wasn't already cold and wet, too.

"What's going on?" he demands, as the Tapu just hover there, watching him. "Why did you bring me here?"

Tapu Koko lets out a shrill sound, _'kokoooo'_, like a summoning shout.

The Z-ring on Ash's wrist suddenly heats up and Ash takes a half a step back, yelping in surprise. He lifts his arm and at the same time the Z-ring starts moving, flying over his hand and towards Tapu Koko. The guardian deity then promptly grabs it and encloses it withing its body. Ash stares at it in stunned disbelief.

"He-hey!" he shouts. "What are you doing?"

Suddenly there are more pokemon than just Tapu Koko and Tapu Fini. Tapu Lele from Akala Island is there, and although Ash has only ever seen it in pictures, he recognizes Tapu Bulu instantly as the fourth guardian deity.

As Tapu Koko holds his Z-ring, the pokemon starts glowing and making a sound that is somewhat musical, while bouncing around almost playfully. Soon, it opens up its body and throws the Z-ring over to Tapu Lele, who proceeds to do a similar move… thing? Ritual?

Ash has no idea.

The ring passes on to Tapu Bulu and finally, to Tapu Fini. When it the flies back towards Ash, he instantly notices that it looks different than before, with a dark design and a slightly bulkier frame. He lets it settle back around his wrist before turning to stare at the deities.

"The Z-ring evolved?" he asks uncertainly. "But… Why?"

Tapu Fini slowly descends, all the way until it's just inches away from Ash, and taps the Z-ring gently. Ash looks at the ring – really _looks_ – and notices that the place for the crystal has changed. It would still fit a normal crystal, but it would also fit something else, something with a different shape…

His mind explodes with just one thought.

_Greninja_.

The thought flashing through his head is so intense, so demanding, that Ash suspects it might not completely be his own. Either way, he takes out Greninja's poke ball and releases it, the frog pokemon coming out battle ready and tense. It looks around, searching for the threat, and after finding none it settles on standing close by on Ash's side.

"Tapu Fini", Ash says, aiming for a stern tone but failing due to his teeth chattering in the freezing rain. "Why did you do that? Why now?"

Tapu Fini just looks at him. Then, it backs off, craning its head to look up into the sky. All the other Tapu do the same, and Ash has just followed their line of sight when a blinding light appears overhead – a circle, or a portal of sorts. It glows in every color and also in none, impossible and brilliantly luminous. Ash shields his eyes from the worst of it, but he can't make himself to look away. He's transfixed by the sight, and every coherent thought in his head is drowned out by the sheer _enormity_ of its aura.

It's beautiful, and also, absolutely terrifying.

_Something_ is coming out of the bright light. Ash squints, trying to figure out which pokemon it is. He thinks it's an onix or a steelix at first, as it is huge and snake-like, but it has too weird of a shape and frankly, it's simply way too big to be even a large-sized steelix.

"Pikaa…" wails Pikachu, low, anxious. Greninja steps closer to Ash, and they transform into Ash-Greninja, more as an instinct than a deliberate action.

"What… _is_ that?" mutters Ash. The closer it gets, the less it looks like a pokemon, and more like something from a surrealistic nightmare. It twists around in the air, groaning in increasing volume, until suddenly its jaws open and it _roars_, and-

Fire, white hot and as fast as sound shoots out of its mouth, scorching the rocky ground into blackness in the far side of the hilltop. The pokemon – the _beast_ pauses for a moment and then seems to decide that it likes it, and it twirls around, spraying fire and chaos everywhere.

Ash feels like his soul is about to leave his body in plain fear.

His brain is moving sluggishly. He watches as the Tapu fly around the monster, trying to contain it with their attacks while avoiding its destructive power. It seems like the attacks from the fairy and water -type Tapu Fini are the most effective, and that would make sense, Ash thinks distractedly, if the creature is at least part fire-type.

His thinking is cut short as the beast stops and turns suddenly, fixing its gleaming eyes at Ash. Ash looks around but there's nothing to hide behind, nowhere to run. His head spins and his legs shake with exhaustion and the numbness the cold has caused, but no matter what…

He has to protect Pikachu and Greninja.

He_ has to._

"Get behind me", he commands, picking up Pikachu from his shoulder and wrapping it up in his arms. "Greninja!"

He can sense the defiance oozing from Greninja. It doesn't budge from his side, and when he moves to step in front of it, as the fire builds in the beast's mouth, it suddenly _pushes_ Ash, sending him tumbling to the side. He smashes into the ground, rolling over a few times, and he watches in horror as white fire shoots directly at Greninja.

"No, Greninja!"

Greninja does something it has never done before. It drops to one knee, throws its arms in front of it and… _water_, as powerful as the fire beam aimed at it shoots out of its being. It's a new move, (hydro pump, Ash mind helpfully supplies), and it's strong enough to deflect the beast's attack.

At least for now.

"Greninja!" Ash shouts, giddy with adrenaline and excitement. "You learnt a new move!"

_I did_, it sends, and is that _smugness_ coming from Greninja?

Ash grins so wide it hurts. "Amazing!"

Their joy is short lived, however. The beast is furious, and it roars, lighting the sky on fire with its flames. It whips it massive body around and Ash has a half a second to put up his Aura as some sort of cover before it smashes its tail-end against him and Greninja, sending them flying with the power of a full-speed freight train. The world turns upside down and over and the only thing Ash knows anymore is Pikachu, its small form still safely cradled in his arms.

.

.

_The Professor_

_._

The flight to Poni Island seems to take forever.

He's sitting next to Burnet and she's holding his hand, squeezing it tightly in hers. Their relationship – the fact that they are dating – it hasn't been official information, but it seems like it comes as a surprise to no one judging by the reactions of Burnet's team. Luckily, they mostly ignore him and their handholding after a while.

"What was that?" yells Faba suddenly, and Kukui is brought back to the present from his spinning thoughts.

"It was fire!" Wicke says urgently, furiously tapping on a hand-held machine. "The ultra-beast has already arrived!"

Kukui leans forward in his seat, trying to catch a glimpse through the windows.

Fire?

_Shit, Ash!_

Burnet's hold tightens and she tugs on his arm. "Sweetie, we're almost there", she says quietly, emphatically. Kukui nods, though he barely hears her.

"Oh gods, look at that ultra-wormhole!" Wicke shouts, sounding weirdly excited. "It's massive! The receiver is going crazy!" She holds the wildly beeping machine in front of her, enthralled by the numbers and figures flashing on its screen. Kukui looks past her, through the front window, and-

He's almost blinded by the _thing_ that must be the ultra-wormhole. The plane shoots past it, turning around in the air and landing on a hilltop few hundred meters from the main commotion. They pour out into the rain and wind and Kukui can only _stare_ in absolute awe and shock.

He sees the ultra-beast first. It's massive, destructive, and the world is burning around it. Then, he sees the Tapu. Tapu Koko, Lele and Bulu are fighting the beast, doing their best to keep it contained within the uninhabited wastelands where they currently are. And it's a good thing they are. Because if a monster like that got loose in the towns…

It would mean the end of the sweet and peaceful Alola.

Kukui searches, searches… But he doesn't see Ash anywhere. Nor Tapu Fini, for that matter. He doesn't know if he should feel relieved or even more worried, but-

"It's beautiful", gasps Lusamine next to him. "Finally, finally!"

She gazes at the ultra-beast like it's her own daughter, proud and emotional, no trace of concern for others in her appearance.

It makes Kukui see red.

"How can you… Ash is_\- a child_ is out there, Lusamine, my student!" he bellows, all manners forgotten. "We don't have time to- to admire this monster from another world!"

Burnet pulls on his arm, shaking her head sharply. "Kukui, don't…"

He ignores her. "What are you going to do to stop _that, _huh? Do you have any plan at all?"

Lusamine looks at him like it's he who has hurt _her_ feelings. "Try to calm down, Professor", she says, emotionless, and turns back to watch the battle.

"We have these special poke balls called beast balls, developed – by me! – to have a greater chance of catching ultra-beasts", explains Faba from behind Kukui. He has a cocky smirk on his face and he's holding one of the special poke balls in his fist, showing it proudly to Kukui. "These will be the secret to our success here, I promise you!"

Kukui knows about the power of poke balls, probably better than most, but the ball still looks insignificant compared to the raging beast in front of them. He wonders if it really can be caught with just that.

He's about to voice his concerns when suddenly Burnet, still hanging from his arm, lets out a shrill scream.

"Who- who is that? Someone is out there, on the ground!"

Kukui knows before he even looks.

Behind all the smoke and fire and dust, there is the small shape of a person, standing tall and challenging the ultra-beast head-on.

Kukui tugs on his hair, desperate. It's Ash.

Of course it is.

.

.

_Ash_

_._

He doesn't black out, but it's close.

After getting hit point-blank by the nightmarish beast, he smashes against a cliff wall and crumbles on the ground. His Aura protected him from the worst of it but, lying breathless on the ground, he still doubts if he can even stand up after that. Pikachu struggles and wails quietly, and when Ash finally lets it go, the pokemon crawls next to him and paws on his face with concern. He feels Greninja moving close by, its body aching as well but more resistant to damage than his human one.

"You guys okay?" he whispers, barely having enough air in his lungs to speak. He tries to crane his head to see where they are, but there's not much to look at other than thick smoke and dust.

_Do not move_, orders Greninja, appearing from somewhere to stand over him. Ash would argue if his ribs didn't hurt so much, so he settles on just nodding and laying still for now.

He doesn't even really want to move, to be honest. Everything hurts and he's just so _tired._

Giving in to the exhaustion, he closes his eyes for a moment, almost dozing off for a second. He doesn't get far, though, before he hears a quiet 'finiii' coming from somewhere close by.

He opens his eyes and Tapu Fini is in front of him. It coos with a demanding tone, and Ash pulls himself back together. Pushing against the rocky ground, he sits up shakily, dark spots dancing in front of his eyes.

"Tapu Fini?" he asks hoarsely. "What is it?"

"Tapu", it says, and its body glows momentarily. "Finii!"

A tiny glowing stone appears and flies towards Ash. Confused, he holds out his hand and it lands on his palm softly, the glow disappearing and revealing a Waterium Z. Ash stares at it, comprehension coming slowly.

"A Waterium Z? Tapu Fini, are you giving it to me?"

The guardian deity nods. It turns around and looks towards the battle Ash can still hear happening behind the smoke and the rocks covering them. Then it looks back at Ash and the crystal, nodding again.

Ash understands.

He has to fight. There's no other choice.

"Alright", he says, resolutely. He sets his jaw and turns to his partner. "Greninja, let's do this. We can use a Z-move to weaken that pokemon."

It's pure determination at that point that lets him stand up again. Greninja stands close by, their arms almost brushing, and it's all the comfort Ash needs.

"You stay back, Pikachu", he tells the small mouse at his feet. "I gotta know that you're safe, or I can't focus on the Z-move, okay?"

The pokemon doesn't look happy, but it nods all the same. "Pika-pika…"

"We will be fine", says the boy, and then they walk straight into the hellfire.

.

It's pure chaos out there.

He can tell straight away that the Tapu are already exhausted from the battle, and the beast is still keeping them more than busy with its attacks. It's only a matter of time before it gets free from them and has the chance to fly off, destroying everything in its way.

That simply _cannot_ happen.

"Hey, you stupid monster!" Ash shouts from the top of his lungs. "Stop fighting the Tapu and look over here!"

The beast stills, twisting its body around to glare at him.

"Oh crap, it heard me", mutters Ash under his breath.

_Do not act so surprised,_ Greninja remarks snidely.

"Eh, whatever."

He presses the Waterium Z onto the bracelet and prepares for the Z-move. "Alright, let's do this!"

Before they can start, something shifts on the Z-ring, and Ash has just enough time to see the crystal morphing, changing shape from a normal Waterium Z into something else. Something that looks like shuriken appears on top of it, and Ash knows what it is even though he doesn't know the name for it. Kukui has told them that very rarely, Z-crystals for specific pokemon are found, and they will create the most powerful Z-moves ever recorded. Ash knows there is one for Pikachu, Pikanium Z, and for Lycanroc, Lycanium Z, so it would make sense for there to be one for Greninja, too. Though Kukui never mentioned that during the lesson about Z-crystals.

What would it be called, then?

_Grenium Z? Hm, maybe Greninjium Z?_

Greninja tugs sharply on their mental link, forcing his exhausted mind to focus. Ash nods, shaking the distractions from his head. He settles on a Z-pose, channeling the energy he can sense flowing freely around them. It builds in him and Greninja, incredibly strong, and it makes him wonder.

"Can you feel it, Greninja?" he asks softly. "The power of Alola?"

Greninja listens. Ash continues, quietly: "I think there was a reason why all that happened in Kalos. I think it happened 'cos we needed to end up here, to do this. Alola needs us today, to _save_ it, and it's gonna loan us the power to do so."

The beast prepares its attack, its jaws widening, fire burning inside it like a blazing furnace. It's about to hit them head-on in seconds.

But they are ready.

"Let's go, Greninja!" shouts Ash. "Our extra full power! Sparkling storm shuriken!"

Greninja grabs the shuriken from its back and as it holds it, it grows in size – double, triple, ten times bigger, until it fills the sky with its gleaming edges and lights the clouds with the glow of a bursting sun. Ash gives it everything he got, and he knows Greninja does too, and they throw it at the beast; hoping, praying, that it is enough.

The move easily slices through the fire beam that the beast is sending their way, and it hits it head-on. The monster _screams_, an awful sound that stops everything in its tracks, and it collapses on the ground with a thundering crack. After the dust settles, its snake-like body is still twitching on the ground, but it's half-conscious anymore, barely there.

Ash's legs give out under him.

Hazily, he blinks at the scene, darkness blurring the edges of his vision. Greninja kneels next to him, and it's not Ash-Greninja anymore, having changed back to its natural form. It holds his shoulder, keeping him grounded.

There's the familiar effect of a poke ball taking in a pokemon, and Ash stares in a confused stupor as the gigantic beast disappears into a tiny poke ball. There are people running towards him, but he can only make out their general shapes through the lingering smoke in the air.

He waves his hand, smiling.

His eyelids weigh a million tons, and he leans against Greninja and decides that it's about time he finally sleeps.

.

.

_The Professor_

_._

He has never seen anything like it.

The move repeats in his head, over and over and over, and he still can't believe it came from Ash and his greninja. That _that much power_ had been contained in the body of those two and formed into a Z-move that has never been seen before.

Ash twitches on the sofa, deep asleep still, and Kukui stops his thinking to just watch him, a soft smile playing in his lips. It's been about two hours since they found his exhausted and barely-awake form in the middle of the battle ground, protected by equally exhausted Greninja and Pikachu. Kukui took him and his injured pokemon to a pokemon center in town, while the Aether Foundation retreated back to their base of operation to analyze all the data they got.

Burnet promised she would come as soon as she could.

Kukui cannot wait.

He looks at the Waterium Z that he dropped on the side table after carrying Ash inside. It looks like an ordinary Z-crystal, but that had been nowhere near an ordinary Z-move. Especially not hydro vortex, which should be the move Waterium Z produces.

He gave the nervous wreck of a Rotom Dex the task of finding out if there has ever been a sighting of a type-specific Z-crystal for greninja. The initial search came up empty, but Rotom is still looking, hovering by the water dispenser in the pokemon center lobby and trying every combo of search term just to keep itself distracted.

Kukui also can't wrap his head around the fact that Ash suddenly has a Z-power ring on his wrist, even though Kukui is certain it was still a normal Z-ring when they returned from Kalos.

He rubs his chin, thoughtful. He really needs to talk to Ash.

As if sensing his thoughts, Ash begins to stir. Kukui scrambles up from his chair and kneels by the sofa, his hands hovering by his sides. Pikachu lifts it head slightly where it's resting on Ash's hip, before curling tighter into itself and continuing snoozing.

"Wha- Greninja…?" mumbles Ash, slowly cracking his eyes open. "Huh?"

Kukui smiles reassuringly. "Hey, Ash. We are in a pokemon center, and everyone's fine."

Ash's eyes open properly, and he looks around with a confused frown. "What room is this?"

"Eh, it's the center's staff room", Kukui chuckles. "Greninja and Pikachu needed healing, and you needed some first aid and a place to sleep, so here we are."

"Oh", says Ash. "Well, if everybody's okay…"

He shifts around on the sofa, waking up alarmingly fast for someone so burnt out. He rubs at his eyes and yawns.

"What happened to the monster pokemon?" he asks then. "Did someone catch it?"

"Monster…? Oh, you must mean the ultra-beast", Kukui replies, surprised. "Yeah, we caught it."

Ash probably has no idea what he was even fighting against, he realizes then. No idea what it was that he saw.

"Ultra-beast?"

"Yeah, that's what they are called. I can explain it to you another time with more detail", Kukui promises, "but first of all, how are you feeling? We didn't take you to a hospital, since… well, you seemed mostly okay, and we thought you might like it better here. Are you experiencing any sharp pain anywhere?

Ash is quiet for a moment, moving his limbs around one after another, and his brow furrows a few times – when something hurts, supposes Kukui.

"I'm okay", Ash concludes then, relaxing back on the pillows. "The thing – the ultra-beast, it hit me pretty hard at one point and that kinda knocked the wind out of me, but I don't think I broke anything. I guess my Aura protected me."

"Good", exhales Kukui. There hadn't been anything other than scratches and bruising on Ash when they checked him over, but he's still worried there might be something more serious they had missed. But as it is, as he seems coherent enough and isn't complaining about any major pain, he supposes they are mostly in the clear. They can go in for a check-up later, when they aren't so damn _tired_.

"Can you tell me about that Z-move you and Greninja performed?" Kukui asks then, since he physically cannot wait any longer to know.

"You mean sparkling storm shuriken?" Ash asks plainly, like it's something everyone knows about.

Kukui blinks. "Spa… sparkling storm _what_?"

"Shuriken", explains Ash. "Like Greninja's water shuriken. Since it was a big one like that, and there was a storm."

Kukui shakes his head slowly.

Ash shrugs, and winces. "Well, I mean, I came up with the name on the spot. Since I dunno if there's a real name for it or anything. But it seemed to fit."

"It does fit, yes", Kukui slowly says. "Did you get the Z-crystal from Tapu Koko again?"

"No, from Tapu Fini", Ash corrects. "It was just a Waterium Z at first, but when we were gonna do the normal Z-move, it changed into something else, and then we were able to do the big Z-move with Greninja!"

"That's amazing", says Kukui, since there's _so much_ research to be done before he can say anything else.

Ash nods firmly. "Yep, it was! We also used the life force of Alola you told me about earlier! It wasn't just me and Greninja, but everyone and everything in Alola that helped us fight that ultra-beast!"

Kukui nods, speechless, and that is when a whole class of kids bursts through the door, yelling that they need to see Ash _right this second_.

.

.

While the class is visiting Ash, Kukui retreats to the lobby to wait for Burnet.

She arrives half an hour later, clothes rumpled and hair astray. She looks gorgeous.

She encloses him in a big, warm hug. "Kukui, sweetie, how are you doing here? You and Ash?"

"Fine, we are fine", he says, the words blurring together with exhaustion. "Ash woke up a bit ago and he seems to be mostly okay. Bruised and shaken, of course, but saved from any major injury."

"That's a one tough kid", states Burnet and Kukui nods empathically. She sits down next to him, her arms flailing wildly. "And that Z-move! Oh my gods, Kukui! What _was_ that?"

Seems like she can't really control her curiosity, either.

Kukui grins mischievously. "Oh, you mean sparkling storm shuriken?" he replies, using the same nonchalant tone Ash had.

"The _what_?"

He laughs at Burnet's wide-eyed look and explains: "Don't worry, that's exactly how I reacted. It's just how Ash called it. He invented it, apparently."

Burnet scratches the side of her head, a smile breaking on her face. "That kid is a menace."

She takes out her smart pad and scrolls trough some of the data. "Anyway, look at this. Sadly, the visual data is lacking due to all the smoke and rain disturbance, but we got some very interesting energy readings. That ultra-beast was an incredibly powerful dual fire and rock -type. No previous data of it is available. Faba and Wicke are updating its information into the system as we speak."

Kukui nods thoughtfully.

"Then, that Z-move we all witnessed…" She's suddenly so excited she's basically shaking. "Incredible! Pokemon moves are more of your specialty, Kukui, but I bet my pension on the fact that there has never been anything even _close to_ _that_ performed. I have never heard of a greninja-specific Z-move, and what makes it even more interesting is the fact that Ash and his greninja were linked in a special form at the same time!"

She pauses to take a breath. "We're very interested to know how _that_ actually affects their power level, and if it could be the reason why the Z-move wasn't just an ordinary hydro vortex. And the fact that they matched the ultra-beast's strength almost toe-to-toe is also super interesting, especially considering Ash wasn't even in full health at that time." Burnet grins, and she glows brighter than the sun. "Kukui, please tell me we can interview Ash about this at some point? Maybe test his abilities, get actual data of the bond-evolution?"

Kukui's hands are suddenly freezing cold and his stomach twist uncomfortably. The smile drops away from his face and he grits his teeth, looking away.

"No, you can't", he says bluntly. "At least not- not yet. Please, just leave him alone."

The scene plays in front of him again, on a horrible loop he can't seem to stop. Ash looking at him with fear, with distrust, backing away like his life depends on it. Ash shouting '_stay away'_, like he thought Kukui was about to grab him and twist him and _hurt_ him.

Ash speaking in a small voice, telling the officers how Lysandre wanted to take control of him, use him to destroy the lives of thousands of people and pokemon.

Lysandre killing himself because Ash refused to submit, refused to work for him.

"Kukui?"

"Let him be", Kukui repeats harshly. "I mean it. Tell that to Lusamine especially. Ash is my student and he's a child and he is _not a test subject_."

He almost shouts the last part, and his voice echoes in the empty lobby. He's breathing hard and he feels cold inside, and the way Burnet looks at him makes it even worse. She has every right to be angry at him after an outburst like that, but she just looks… sad. Compassionate.

"I'm sorry", he whispers, hollow.

She grabs his hand, rubbing some warmth into it.

"I don't know much about what happened in Kalos", she says quietly. "But I hope you and Ash can tell me, someday."

She leans forward, searching eye contact with him. "I will tell Lusamine that we are not investigating Ash any further, not unless he asks himself, okay? I will make sure he stays safe."

Kukui nods, unable to speak.

"I love you, sweetie. You're doing just fine."

Kukui closes his eyes and he can hear the kids laughing loudly in the adjacent room.

He _really_ hopes she's right.

.

.

_Ash_

_._

Professor Burnet is great.

She's a lot of fun, very caring, and doesn't ask too many questions – which is a bit strange but also nice, in Ash's opinion. She also gets along _really well_ with Professor Kukui. She starts basically living with them after the ultra-beast incident, and it doesn't look like she's leaving anytime soon. It's a huge comfort for Kukui too, Ash notices, who had seemed a bit off from the moment they came back from Kalos. She seems to make him calmer, happier, more relaxed.

Which is good. Ash dislikes it when people walk on eggshells around him.

Ash is sitting on the beach near Professor Kukui's house, gazing over the calmly lilting waves, into the pastel pink light of the horizon. Greninja is lounging next to him and Pikachu is on his lap, and they are trying out some techniques Kukui and Burnet taught them.

_Recharging_, they call it. Deep relaxing; breathing in the life force of Alola.

It works quite well. It makes Ash feel more in tune with his Aura, with Alola's Aura, and it helps him find the balance between it all. When he meditates, he doesn't think about anything; he just listens, _absorbs._

Pikachu is asleep on his crossed legs, and the sunset throws shades of yellows over the sky. He needs to get back inside before dark or the Professor is going to freak out.

Ash scoops up Pikachu into his arms and stands up gingerly. It's been a couple of weeks, and his body is slowly healing along with his mind. Every day it gets better.

He's made peace with the ghost of Lysandre. As without him, they couldn't have saved Alola from a disaster.

He still gets nightmares sometimes, and he startles when Kukui accidentally dwarfs him with his tall frame, and he distrust people who act too interested around Greninja, but he thinks he can live with that. It's just another challenge to overcome.

He shares a grin with Greninja as they jog back to the porch where the Professors are waiting.

Ash_ loves_ challenges.

.

* * *

**Alternative summary: Ash discovers a new ultra-beast, invents a new Z-move and saves Alola on the side, all in a days work.**

**.**

**Yes, I admit, the main motivation behind this fic was to give Ash-Greninja a Z-move XD**

**.**

**Some headcanons:  
I think the morphed "Ash-Greninja" crystal could be called either Greninjashium Z or Greninjashinium Z (like there's a Pikashinium Z for Ash-Pikachu), and if a normal greninja-specific crystal is ever discovered, it could be just Greninjium Z.**

**As for the name of that Z-move... It's up to debate if Ash's suggestion is a worthy option XD**


End file.
